There is no patron saint of divorce but these saints are the patron saints of divorced people:FabiolaGuntramnusHelena
As per the Patron Saint Index, William of York is a saint but not currently a patron saint.
There is no patron saint of bullying or against bullying.
Yes he is the patron saint of repented thieves.
There is no patron saint of children's health but the Infant of Prague is the patron saint of good health.
The patron saints of unborn children are Saint Joseph and Saint Gerard Majella.
Saint Nicholas of Myra is the patron saint of children, scholars and penitent thieves as well as a number of other causes. For a complete list of his patronages, click on this link.
As per the Patron Saints Index, the patron saints of unborn children are Saint Gerard Majella and Saint Joseph.
I see no specific saint for healing of children. However, St. Brigid of Ireland is considered as the patron saint of healers.
There is no officially recognized patron saint of divorce in the Catholic Church. However, some people turn to Saint Rita of Cascia, known for her role in difficult marriages and her own challenging life circumstances, for intercession in matters related to troubled relationships. Additionally, Saint Jude, the patron saint of lost causes, is sometimes invoked for help in seemingly hopeless situations, including divorce.
The patron saint against autism is St. Ubaldus Baldassini.
There are patron saints of children or orphans or social workers but no patron saint of child custody.